Scientists at The University of Texas MD Anderson Cancer Center may have discovered why some brain cancer patients develop resistance to standard treatments including radiation and the chemotherapy agent temozolomide.

Simply put, it’s all in their DNA, and it could open up new avenues for treating certain kinds of brain cancer.

DNA, the body’s essential storehouse for genetic information. In the case of glioblastoma, the most common and aggressive type of glioma or brain cancer, it can also allow the disease to progress more quickly when it is “enhanced,” allowing damaged or mutated cancer cells to repair themselves.

“A major obstacle to effective treatment is acquired resistance to treatment,” said Wei Zhang, Ph.D., professor of Pathology. “Enhanced DNA repair can allow these cancer cells to survive, contributing to resistance and tumour recurrence. We have identified Aktr3 as having the ability to robustly stimulate glioma progression.”

Akts are proteins known as kinases that regulate cell signalling. They’re involved in many bodily processes such as cell growth, cell death and tumour growth. Akts are thought to contribute to the development and progression of many cancers including prostate, breast, liver, colorectal and others. One form of this protein, Akt3, appears to be especially prevalent in the brain.

Zhang’s findings describe his team’s study results showing how Akt3 activates key DNA repair pathways.

In Zhang’s research, he reveals that Akt3 is tied to DNA’s “repair panel,” somehow boosting activation of DNA repair proteins, leading to increased DNA repair, and subsequently to cancer treatment resistance.

“This activation led to enhanced survival of brain tumour cells following radiation or treatment with temozolomide,” said Zhang. “Our work has potentially broad application to multiple cancer types in which Akt3 is expressed. Blocking this pathway may help prevent or alleviate therapeutic resistance resulting from enhanced DNA repair.” MD Anderson Cancer Center

A study by researchers at IRB Barcelona explains the basis for the classification of colon tumours in good or bad prognosis by analysing the tissue surrounding the tumour cells.

The scientists are currently developing a test that enables the identification of patients at risk of relapse after surgical removal of the tumour by measuring 4-6 genes expressed by the tumour microenvironment.

The researchers also propose to test in patients a particular drug that blocks the metastatic capacity of colorectal cancers in mice.

This drug has been tested using novel technology that allows the growth of mini colon cancers, also known as organoids, derived from patient samples.
About 40–50% of all colorectal patients relapse in the form of metastasis. In the last three years, several molecular classifications have been proposed to identify colorectal cancer patients at risk of relapse. Scientists headed by ICREA researcher Eduard Batlle at the Institute for Research in Biomedicine (IRB Barcelona) explain why these classifications work and reveal, in fact, that they can be simplified and improved by looking exclusively at the genes that are expressed in the tissue around the tumour, known as the stroma or tumour microenvironment.

“We have re-evaluated the classifications under our perspective and confirmed that colon cancer relapse occurs in patients in which tumour cells have the capacity to disrupt the tissue surrounding the tumour,” explains Eduard Batlle, head of the Colorectal Cancer Laboratory at IRB Barcelona. The team of scientists have examined the genetic profile of around 1,000 tumours from patients all over the world. “The conclusion is indisputable. The key to the classifications lies in whether the stroma of the tumour is altered or not and it is this property that confers malignancy to colon tumours. Patients with unaltered stroma are essentially cured after surgery.”

This new approach to addressing different types of colon tumour will soon have a practical application for doctors. On one hand, the scientists demonstrate that tumour cells communicate with the stroma through the hormone TGF-beta and that metastasis could be prevented in these patients by interfering with this communication. “We propose exploring the possibility of using TGF-beta inhibitors to treat colon cancer”. Several TGF-beta inhibitors are being tested for other kinds of tumours. “The data are impressive. It would be most pertinent for oncologists and pharmaceutical companies to come to an agreement in order to start clinical assays in patients with poor prognosis colon cancer” says Alexandre Calon, postdoctoral researcher and first author of the article. To test the use of these inhibitors, the scientists at IRB Barcelona have developed technology that allows them to grow mini colon tumours in vitro, also known as organoids, from samples taken from patients. “These organoids reproduce the behaviour of the original tumour and are therefore a powerful tool for personalised cancer treatment,” explains Batlle. 

Furthermore, the IRB Barcelona researchers are very close to achieving a diagnostic test named Colostage to identify those patients at the greatest risk of a relapse in the form of metastasis. “By focusing on the genetic programme of the tissue surrounding the tumour we can identify the vast majority of patients that will experience relapse. This would allow better discrimination of which patients to treat and follow up, as the use of radiotherapy or chemotherapy would benefit only this group” ensures the researcher. In addition, this test will help identify those patients more likely to benefit from the use of TGF-beta inhibitors in clinical trials. IRB Barcelona

Brown University biologists have determined how the loss of a gene in male mice results in the premature exhaustion of their fertility. Their fundamental new insights into the complex process of sperm generation may have direct applications to a similar loss of fertility in men.

What the team discovered is that the loss of the gene that makes the protein TAF4b causes a deficit in the number of progenitor cells at an embryonic stage of a male mouse’s reproductive development. Lacking those important precursor cells means that the mice struggle to develop a robust stem cell infrastructure to sustain sperm production for the long term. The affected mice are fertile at first, but quickly deplete the limited sperm supply that they can generate.

“What’s fascinating about these mice is they can reproduce,” said Richard Freiman, senior author of the new study in the journal Stem Cells. “Mice can usually reproduce until they are two years old, but these mice can only reproduce until they are four months old.”

TAF4b is a protein that affects how genes are regulated and transcribed, and its absence has profound impacts on the reproductive system. In previous work, Freiman’s research group has shown that female mice without TAF4b are totally infertile and that their ovaries age prematurely. But in experiments with males, led by lab members Lindsay Lovasco and Eric Gustafson, the effect proved more subtle.

Sperm generation follows from a complex chain of events that the research shows begins before a male mouse is even born. In their experiments, the team compared the development of mice with and without the TAF4b gene. In mice with TAF4b, progenitor cells for sperm in the male embryo arise and proliferate normally, laying the groundwork in the testes for a robust pool of spermatogonial stem cells to develop. Those stem cells are the ones that produce a renewable supply of sperm. Without TAF4b, there were fewer progenitor cells and consequently fewer stem cells. They still produce sperm at first, but they can’t renew production for the long haul. Ultimately the testes, which develop normally, become unproductive and atrophy.

What’s not yet clear from the research is why the process fades out rather than just continuing, albeit at a very low level of productivity. One possibility is the low supply of spermatogonial stem cells drives the body to invest all its meagre resources in immediate sperm production, leaving none of the stem cells in a more flexible state that can perpetually renew the supply. Another possibility is that regardless of supply, TAF4b is simply needed to see the renewal process through, for instance by maintaining some stem cells in their regenerative state.

Not only do humans have a gene for TAF4b, but a coincidental study last year in the Journal of Medical Genetics provides evidence that it also matters for sperm count. That research reported that four Turkish brothers who carried a mutation in the TAF4b gene had low sperm counts. Their mutation was in the same region of their gene as the one Freiman’s team generated in the mice.

“The human implications are very exciting,” he said. “It is possible that those men, as teenagers, were able to make functional sperm.”

Certainly more research is needed, Freiman said, but if TAF4b mutation plays out in men the way it plays out in mice, his hope is that detecting the mutation in teenage boys could allow doctors to freeze their sperm so that when they are older and want to have children, they could draw on that banked supply. Brown University

Analysing a puzzling multisystem disorder in three children, genetic experts have identified a new syndrome, shedding light on key biological processes during human development. The research also provides important information to help caregivers manage the disorder, and may offer clues to eventually treating it.

“This syndrome illuminates a very important pathway in early human development — a sort of master switch that controls many other genes,” said study leader Ian D. Krantz, MD, co-director of the Individualized Medical Genetics Center at The Children’s Hospital of Philadelphia (CHOP). Krantz, a medical geneticist, is an attending physician in CHOP’s comprehensive human genetics program.

The investigators named the disorder CHOPS syndrome, with the acronym representing a group of symptoms seen in the affected children: cognitive impairment and coarse facies (facial features), heart defects, obesity, pulmonary involvement, short stature and skeletal dysplasia (abnormal bone development).

The central research finding is that mutations in the gene AFF4 disrupt a crucial group of proteins called the super elongation complex (SEC). The SEC controls the transcription process by which DNA is copied into RNA, enabling genes to be expressed in a developing embryo. The timing of this biological process is tightly regulated, so anything that interferes with this timing can disturb normal development in a variety of ways.

“Because the SEC involves such a crucial process in cell biology, it has long been a focus of study, particularly in cancer,” said Krantz. “CHOPS syndrome is the first example of a human developmental disorder caused by germline mutations in the SEC.”

Originating in the embryo, germline mutations are passed along to every cell in a developing organism, with harmful effects in multiple organs and biological systems. The mutated AFF4 gene produces mutated proteins, which then accumulate and cause a cascade of abnormalities in other genes controlled by AFF4.

“AFF4 has a critical role in human development, regulating so many other genes,” said Krantz. “When it is mutated, it can damage the heart and skeleton, and lead to intellectual disability, among other effects.”

The current study sequenced the exomes (the protein-coding portions of DNA) of three unrelated children treated at CHOP for a complex developmental disorder. All three patients had some symptoms similar to those found in patients with Cornelia deLange syndrome (CdLS), a rare multisystem disease long studied at CHOP. Krantz led research that discovered the first causative gene for CdLS in 2004.

The research team’s DNA analysis and studies of gene expression patterns determined that the new syndrome is genetically distinct from CdLS, even while sharing some common molecular mechanisms. Although only the three children in the study are known to definitely have CHOPS syndrome, Krantz expects diagnoses to increase with the dissemination of this discovery and the ongoing spread of faster, lower-cost gene-sequencing technology.

The research findings offer practical and emotional benefits for families, said Krantz. Physicians may now order more appropriate tests to monitor and manage specific medical issues arising from CHOPS syndrome. “This also means families and children can end their ‘diagnostic odyssey’ — the frustrating procession of tests and unsuccessful treatments that often occurs in trying to find an answer for families who have a child affected by a complex, undiagnosed disorder,” he added. CHOP Research Institute

Researchers at Okayama demonstrate that injection of a virus solution followed by tumour removal can eradicate cancer metastasis in lymph nodes without the need for preventative surgery.
While early-stage gastrointestinal cancers can be treated non-surgically, once the cancer has invaded to a particular depth, preventative – ‘prophylactic’ – surgery is routine. The frequency of lymph node metastasis increases significantly once the cancer has penetrated the submucosal layers, and as there is no way of determining whether the cancer has metastasized in the lymph nodes they will be surgically removed just in case. Now researchers at Okayama University and the University of California in San Diego have demonstrated that injection of a viral solution can eradicate lymph node metastasis making prophylactic surgery unnecessary.
To treat early stage cancers a saline solution is injected creating a fluid cushion, which raises and isolates the tumour. The tumour is then readily removed by equipment through a standard endoscopic viewing tube inserted in the gastrointestinal tract. However if the cancer has already penetrated the submucosal layer it will be prone to relapse in the lymphatic system.
Toshiyoshi Fujiwara and his colleagues adapted the standard endoscopic treatment by injecting a solution of Telomelysin – a virus known to kill epithelial and mesenchymal malignant cells – instead of saline solution.  They tested the treatment in a mouse model, injecting green-fluorescent-protein-labelled cancer cells into the submucosal layers of the rectum, which developed lymph node metastasis. Fluorescence imaging showed that cancer cells were successfully eliminated by the treatment with virus solution, in contrast to mice treated with saline solution instead. In addition, treated mice showed no relapse four weeks after the treatment
In their report of the results the researchers conclude, “From a clinical view point, this new, simple, and robust strategy is a more realistic and promising bench-to-bedside translation than prophylactic surgery for ablation of potential lymph node metastases in early gastrointestinal cancer patients.”
Early stage gastrointestinal cancers are defined by the level of the cancer invasion reaching no further than the submucosa. Endoscopic treatment removes these tumours by dissecting the submucosal layers.
For esophageal gastric and colorectal submucosally invaded cancers, the frequency at which the cancer is found to metastasize in the lymph nodes is approximately 10 to 20%. The lymphatic system distributes fluids, proteins, chemicals, cells and drugs. This makes it a major pathway for the spread of metastatic cancers so that cancerous invasion of the lymphatic system is particularly problematic. It is very difficult to determine whether the cancer has metastases in the lymph nodes. As a result lymph node surgery just in case is routine when treating esophageal gastric and colorectal submucosal cancers, even though in many cases it may not have been necessary.
Previous research has demonstrated that certain viruses replicate in cancer cells and break them down, and may be developed for cancer treatments. The researchers further exploited the role of the lymph system in mediating proteins and fluids, a function which makes it more prone to exposure to a virus injected in the surrounding area. They experimented with Telomelysin – a telomerase-dependent, tumour-killing replicating adenoviral agent (OBP-301). The virus is known to kill epithelial and mesenchymal malignant cells.  
The researchers first tested the virus on green-fluorescent-protein-labelled colorectal cancer cell lines with. Using fluorescence imaging, they observed rapid cell death in response to injection with the virus while there was no such response in cell lines treated with mutant strains of the virus that had replication deficiencies.
The researchers demonstrated how their treatment exploited the lymph node function using mouse models injected with red-fluorescent-protein-labelled lymph node metastasized cancer cells. After six days the virus labelled with green fluorescent protein was injected and fluorescence images showed the position of the virus coincided with the metastatic foci in the lymph nodes.

Kikuchi S, Kishimoto H, Tazawa H, Hashimoto Y, Kuroda S, Nishizaki M, Nagasaka T, Shirakawa Y, Kagawa S, Urata Y, Hoffman RM, Fujiwara T: Biological Ablation of Sentinel Lymph Node Metastasis in Submucosally Invaded Early Gastrointestinal Cancer. Mol Ther. 2014 Dec 19.